The Level of Cytokines in the Vitreous Body of Severe Proliferative Diabetic Retinopathy Patients Undergoing Posterior Vitrectomy

Abstract

Objective: The objective of the study was to compare cytokine levels in the vitreous body of patients with proliferative diabetic retinopathy (PDR) undergoing posterior vitrectomy. Patients and methods: The study included 39 patients (39 eyes) undergoing pars plana vitrectomy (PPV). Patients were divided into three groups: patients with proliferative diabetic retinopathy (PDR) without aflibercept injection prior to the surgery, PDR patients administered aflibercept injection prior to the surgery, and patients without diabetes mellitus (control group). All patients underwent a comprehensive eye examination one day before and 3 weeks after the surgery, including measurements of: best-corrected visual acuity (BVCA) and intraocular pressure (IOP), slit-lamp examination and spectral domain optical coherence tomography (SOCT). Concentrations of cytokines: IL-6, IL-8, IL-12p70, TNF, IL-10, IL-1β were measured in the vitreous body of patients with BD™ Cytometric Bead Array (CBA) Human Inflammatory Cytokines Kit. Results: PDR patients who received pretreatment with aflibercept injection showed significantly lower concentrations of IL-12p70, TNF, IL-10 and IL-1β in the vitreous body compared to the control group. Meanwhile, patients without prior aflibercept injection had a significantly higher concentration of IL-8. There was also a significant positive correlation between IOP before PPV and IL-8 concentration in both PDR patients’ groups. Conclusion: Findings of our study suggest an important role of IL-8 in the development of severe PDR. Aflibercept administration on the day before elective vitrectomy facilitated the surgery.

STAT3 activation in circulating myeloid-derived cells contributes to retinal microvascular dysfunction in diabetes

“…When macrophages or other immune cells migrate to the ischemic retina, they may undergo phenotypic switch and express pSTAT3. Cytokines IL-6, IL-17 and growth factor VEGF and PDGF are potent activators of STAT3, and the vitreous levels of these cytokines/growth factors were significantly higher in PDR patients compared with those in cataract patients [44–46]. The role of pSTAT3 in the pathogenesis of PDR warrants further investigation.…”

The Vitreous Ecosystem in Diabetic Retinopathy: Insight into the Patho-Mechanisms of Disease

“…Analytical results have been mixed regarding the vitreous and serum correlation with different cytokine levels [127,138,142]. Interleukin-6 and interleukin-8 vitreous levels have been shown to be consistently elevated in PDR eyes [24,27,41,132,138,142,143]. Koskela et al showed that IL-6 and IL-8 levels in the vitreous were significantly elevated vs. serum in PDR, and also elevated compared to non-diabetic controls, suggestive of a local role for both of these inflammatory cytokines in PDR [132].…”

“…IL-10 (cytokine synthesis inhibitory factor), an anti-inflammatory cytokine, has been shown to be elevated, decreased, and also unchanged in the vitreous in PDR [24,40,43,113,120,[131][132][133]138,143,148]. The reason for this is not entirely clear but may be partially due to varying sampling methods and patient co-morbidities that could alter the immune system [133].…”

Pro-inflammatory cytokine profile is present in the serum of Mexican patients with different stages of diabetic retinopathy secondary to type 2 diabetes

“…It has been reported that pro-inflammatory cytokines and other markers such as C reactive protein are elevated in the serum, vitreous humour, aqueous humour and tear samples of patients with DR. [9][10][11][12][13] Other reports have shown that the suppression of some cytokines can protect the pathological changes of retinal capillaries in animal models. 14 All those studies support the hypothesis that DR behaves as a low-grade subclinical inflammatory disease.…”